content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2012, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
   * Other names may be trademarks of their respective owners.]
   *
   * -----------------
   * ChartDeleter.java
   * -----------------
    * (C) Copyright 2002-2012, by Richard Atkinson and Contributors.
   *
   * Original Author:  Richard Atkinson;
   * Contributor(s):   -;
   *
   * Changes
   * -------
   * 19-Aug-2002 : Version 1;
   * 17-Oct-2002 : Fixed errors reported by Checkstyle (DG);
   * ------------- JFREECHART 1.0.x ---------------------------------------------
   * 02-Feb-2007 : Removed author tags all over JFreeChart sources (DG);
   *
   */
  
  package org.jfree.chart.servlet;
  
  import java.io.File;
  import java.io.Serializable;
  import java.util.List;
  
  import javax.servlet.http.HttpSessionBindingEvent;
  import javax.servlet.http.HttpSessionBindingListener;
  
  /**
   * Used for deleting charts from the temporary directory when the users session
   * expires.
   */
  public class ChartDeleter implements HttpSessionBindingListener, Serializable {
  
      /** The chart names. */
      private List<String> chartNames = new java.util.ArrayList<String>();
  
      /**
       * Blank constructor.
       */
      public ChartDeleter() {
          super();
      }
  
      /**
       * Add a chart to be deleted when the session expires
       *
       * @param filename  the name of the chart in the temporary directory to be
       *                  deleted.
       */
      public void addChart(String filename) {
          this.chartNames.add(filename);
      }
  
      /**
       * Checks to see if a chart is in the list of charts to be deleted
       *
       * @param filename  the name of the chart in the temporary directory.
       *
       * @return A boolean value indicating whether the chart is present in the
       *         list.
       */
      public boolean isChartAvailable(String filename) {
          return (this.chartNames.contains(filename));
      }
  
      /**
       * Binding this object to the session has no additional effects.
       *
       * @param event  the session bind event.
       */
      @Override
      public void valueBound(HttpSessionBindingEvent event) {
          // do nothing
      }
  
      /**
       * When this object is unbound from the session (including upon session
       * expiry) the files that have been added to the ArrayList are iterated
       * and deleted.
       *
       * @param event  the session unbind event.
       */
      @Override
      public void valueUnbound(HttpSessionBindingEvent event) {
          File tempDir = new File(System.getProperty("java.io.tmpdir"));
          for (String filename : this.chartNames) {
              File file = new File(tempDir, filename);
              if (file.exists()) {
                  file.delete();
              }
          }
      }
  
  }
  